* @author Jeremy Livingston */ class CaptchaBuilder implements CaptchaBuilderInterface { /** * @var array */ protected $fingerprint = array(); /** * @var bool */ protected $useFingerprint = false; /** * @var array */ protected $textColor = null; /** * @var array */ protected $backgroundColor = null; /** * @var array */ protected $backgroundImages = array(); /** * @var resource */ protected $contents = null; /** * @var string */ protected $phrase = null; /** * @var PhraseBuilderInterface */ protected $builder; /** * @var bool */ protected $distortion = true; /** * The maximum number of lines to draw in front of * the image. null - use default algorithm */ protected $maxFrontLines = null; /** * The maximum number of lines to draw behind * the image. null - use default algorithm */ protected $maxBehindLines = null; /** * The maximum angle of char */ protected $maxAngle = 8; /** * The maximum offset of char */ protected $maxOffset = 5; /** * Is the interpolation enabled ? * * @var bool */ protected $interpolation = true; /** * Ignore all effects * * @var bool */ protected $ignoreAllEffects = false; /** * Allowed image types for the background images * * @var array */ protected $allowedBackgroundImageTypes = array('image/png', 'image/jpeg', 'image/gif'); /** * The image contents */ public function getContents() { return $this->contents; } /** * Enable/Disables the interpolation * * @param $interpolate bool True to enable, false to disable * * @return CaptchaBuilder */ public function setInterpolation($interpolate = true) { $this->interpolation = $interpolate; return $this; } /** * Temporary dir, for OCR check */ public $tempDir = 'temp/'; public function __construct($phrase = null, PhraseBuilderInterface $builder = null) { if ($builder === null) { $this->builder = new PhraseBuilder; } else { $this->builder = $builder; } if ($phrase === null) { $phrase = $this->builder->build(); } $this->phrase = $phrase; } /** * Setting the phrase */ public function setPhrase($phrase) { $this->phrase = (string) $phrase; } /** * Enables/disable distortion */ public function setDistortion($distortion) { $this->distortion = (bool) $distortion; return $this; } public function setMaxBehindLines($maxBehindLines) { $this->maxBehindLines = $maxBehindLines; return $this; } public function setMaxFrontLines($maxFrontLines) { $this->maxFrontLines = $maxFrontLines; return $this; } public function setMaxAngle($maxAngle) { $this->maxAngle = $maxAngle; return $this; } public function setMaxOffset($maxOffset) { $this->maxOffset = $maxOffset; return $this; } /** * Gets the captcha phrase */ public function getPhrase() { return $this->phrase; } /** * Returns true if the given phrase is good */ public function testPhrase($phrase) { return ($this->builder->niceize($phrase) == $this->builder->niceize($this->getPhrase())); } /** * Instantiation */ public static function create($phrase = null) { return new self($phrase); } /** * Sets the text color to use */ public function setTextColor($r, $g, $b) { $this->textColor = array($r, $g, $b); return $this; } /** * Sets the background color to use */ public function setBackgroundColor($r, $g, $b) { $this->backgroundColor = array($r, $g, $b); return $this; } /** * Sets the ignoreAllEffects value * * @param bool $ignoreAllEffects * @return CaptchaBuilder */ public function setIgnoreAllEffects($ignoreAllEffects) { $this->ignoreAllEffects = $ignoreAllEffects; return $this; } /** * Sets the list of background images to use (one image is randomly selected) */ public function setBackgroundImages(array $backgroundImages) { $this->backgroundImages = $backgroundImages; return $this; } /** * Draw lines over the image */ protected function drawLine($image, $width, $height, $tcol = null) { if ($tcol === null) { $tcol = imagecolorallocate($image, $this->rand(100, 255), $this->rand(100, 255), $this->rand(100, 255)); } if ($this->rand(0, 1)) { // Horizontal $Xa = $this->rand(0, $width/2); $Ya = $this->rand(0, $height); $Xb = $this->rand($width/2, $width); $Yb = $this->rand(0, $height); } else { // Vertical $Xa = $this->rand(0, $width); $Ya = $this->rand(0, $height/2); $Xb = $this->rand(0, $width); $Yb = $this->rand($height/2, $height); } imagesetthickness($image, $this->rand(1, 3)); imageline($image, $Xa, $Ya, $Xb, $Yb, $tcol); } /** * Apply some post effects */ protected function postEffect($image) { if (!function_exists('imagefilter')) { return; } if ($this->backgroundColor != null || $this->textColor != null) { return; } // Negate ? if ($this->rand(0, 1) == 0) { imagefilter($image, IMG_FILTER_NEGATE); } // Edge ? if ($this->rand(0, 10) == 0) { imagefilter($image, IMG_FILTER_EDGEDETECT); } // Contrast imagefilter($image, IMG_FILTER_CONTRAST, $this->rand(-50, 10)); // Colorize if ($this->rand(0, 5) == 0) { imagefilter($image, IMG_FILTER_COLORIZE, $this->rand(-80, 50), $this->rand(-80, 50), $this->rand(-80, 50)); } } /** * Writes the phrase on the image */ protected function writePhrase($image, $phrase, $font, $width, $height) { $length = strlen($phrase); if ($length === 0) { return imagecolorallocate($image, 0, 0, 0); } // Gets the text size and start position $size = $width / $length - $this->rand(0, 3) - 1; $box = imagettfbbox($size, 0, $font, $phrase); $textWidth = $box[2] - $box[0]; $textHeight = $box[1] - $box[7]; $x = ($width - $textWidth) / 2; $y = ($height - $textHeight) / 2 + $size; if (!count($this->textColor)) { $textColor = array($this->rand(0, 150), $this->rand(0, 150), $this->rand(0, 150)); } else { $textColor = $this->textColor; } $col = imagecolorallocate($image, $textColor[0], $textColor[1], $textColor[2]); // Write the letters one by one, with random angle for ($i=0; $i<$length; $i++) { $box = imagettfbbox($size, 0, $font, $phrase[$i]); $w = $box[2] - $box[0]; $angle = $this->rand(-$this->maxAngle, $this->maxAngle); $offset = $this->rand(-$this->maxOffset, $this->maxOffset); imagettftext($image, $size, $angle, $x, $y + $offset, $col, $font, $phrase[$i]); $x += $w; } return $col; } /** * Try to read the code against an OCR */ public function isOCRReadable() { if (!is_dir($this->tempDir)) { @mkdir($this->tempDir, 0755, true); } $tempj = $this->tempDir . uniqid('captcha', true) . '.jpg'; $tempp = $this->tempDir . uniqid('captcha', true) . '.pgm'; $this->save($tempj); shell_exec("convert $tempj $tempp"); $value = trim(strtolower(shell_exec("ocrad $tempp"))); @unlink($tempj); @unlink($tempp); return $this->testPhrase($value); } /** * Builds while the code is readable against an OCR */ public function buildAgainstOCR($width = 150, $height = 40, $font = null, $fingerprint = null) { do { $this->build($width, $height, $font, $fingerprint); } while ($this->isOCRReadable()); } /** * Generate the image */ public function build($width = 150, $height = 40, $font = null, $fingerprint = null) { if (null !== $fingerprint) { $this->fingerprint = $fingerprint; $this->useFingerprint = true; } else { $this->fingerprint = array(); $this->useFingerprint = false; } if ($font === null) { $font = __DIR__ . '/Font/captcha'.$this->rand(0, 5).'.ttf'; } if (empty($this->backgroundImages)) { // if background images list is not set, use a color fill as a background $image = imagecreatetruecolor($width, $height); if ($this->backgroundColor == null) { $bg = imagecolorallocate($image, $this->rand(200, 255), $this->rand(200, 255), $this->rand(200, 255)); } else { $color = $this->backgroundColor; $bg = imagecolorallocate($image, $color[0], $color[1], $color[2]); } $this->background = $bg; imagefill($image, 0, 0, $bg); } else { // use a random background image $randomBackgroundImage = $this->backgroundImages[rand(0, count($this->backgroundImages)-1)]; $imageType = $this->validateBackgroundImage($randomBackgroundImage); $image = $this->createBackgroundImageFromType($randomBackgroundImage, $imageType); } // Apply effects if (!$this->ignoreAllEffects) { $square = $width * $height; $effects = $this->rand($square/3000, $square/2000); // set the maximum number of lines to draw in front of the text if ($this->maxBehindLines != null && $this->maxBehindLines > 0) { $effects = min($this->maxBehindLines, $effects); } if ($this->maxBehindLines !== 0) { for ($e = 0; $e < $effects; $e++) { $this->drawLine($image, $width, $height); } } } // Write CAPTCHA text $color = $this->writePhrase($image, $this->phrase, $font, $width, $height); // Apply effects if (!$this->ignoreAllEffects) { $square = $width * $height; $effects = $this->rand($square/3000, $square/2000); // set the maximum number of lines to draw in front of the text if ($this->maxFrontLines != null && $this->maxFrontLines > 0) { $effects = min($this->maxFrontLines, $effects); } if ($this->maxFrontLines !== 0) { for ($e = 0; $e < $effects; $e++) { $this->drawLine($image, $width, $height, $color); } } } // Distort the image if ($this->distortion && !$this->ignoreAllEffects) { $image = $this->distort($image, $width, $height, $bg); } // Post effects if (!$this->ignoreAllEffects) { $this->postEffect($image); } $this->contents = $image; return $this; } /** * Distorts the image */ public function distort($image, $width, $height, $bg) { $contents = imagecreatetruecolor($width, $height); $X = $this->rand(0, $width); $Y = $this->rand(0, $height); $phase = $this->rand(0, 10); $scale = 1.1 + $this->rand(0, 10000) / 30000; for ($x = 0; $x < $width; $x++) { for ($y = 0; $y < $height; $y++) { $Vx = $x - $X; $Vy = $y - $Y; $Vn = sqrt($Vx * $Vx + $Vy * $Vy); if ($Vn != 0) { $Vn2 = $Vn + 4 * sin($Vn / 30); $nX = $X + ($Vx * $Vn2 / $Vn); $nY = $Y + ($Vy * $Vn2 / $Vn); } else { $nX = $X; $nY = $Y; } $nY = $nY + $scale * sin($phase + $nX * 0.2); if ($this->interpolation) { $p = $this->interpolate( $nX - floor($nX), $nY - floor($nY), $this->getCol($image, floor($nX), floor($nY), $bg), $this->getCol($image, ceil($nX), floor($nY), $bg), $this->getCol($image, floor($nX), ceil($nY), $bg), $this->getCol($image, ceil($nX), ceil($nY), $bg) ); } else { $p = $this->getCol($image, round($nX), round($nY), $bg); } if ($p == 0) { $p = $bg; } imagesetpixel($contents, $x, $y, $p); } } return $contents; } /** * Saves the Captcha to a jpeg file */ public function save($filename, $quality = 90) { imagejpeg($this->contents, $filename, $quality); } /** * Gets the image GD */ public function getGd() { return $this->contents; } /** * Gets the image contents */ public function get($quality = 90) { ob_start(); $this->output($quality); return ob_get_clean(); } /** * Gets the HTML inline base64 */ public function inline($quality = 90) { return 'data:image/jpeg;base64,' . base64_encode($this->get($quality)); } /** * Outputs the image */ public function output($quality = 90) { imagejpeg($this->contents, null, $quality); } /** * @return array */ public function getFingerprint() { return $this->fingerprint; } /** * Returns a random number or the next number in the * fingerprint */ protected function rand($min, $max) { if (!is_array($this->fingerprint)) { $this->fingerprint = array(); } if ($this->useFingerprint) { $value = current($this->fingerprint); next($this->fingerprint); } else { $value = mt_rand($min, $max); $this->fingerprint[] = $value; } return $value; } /** * @param $x * @param $y * @param $nw * @param $ne * @param $sw * @param $se * * @return int */ protected function interpolate($x, $y, $nw, $ne, $sw, $se) { list($r0, $g0, $b0) = $this->getRGB($nw); list($r1, $g1, $b1) = $this->getRGB($ne); list($r2, $g2, $b2) = $this->getRGB($sw); list($r3, $g3, $b3) = $this->getRGB($se); $cx = 1.0 - $x; $cy = 1.0 - $y; $m0 = $cx * $r0 + $x * $r1; $m1 = $cx * $r2 + $x * $r3; $r = (int) ($cy * $m0 + $y * $m1); $m0 = $cx * $g0 + $x * $g1; $m1 = $cx * $g2 + $x * $g3; $g = (int) ($cy * $m0 + $y * $m1); $m0 = $cx * $b0 + $x * $b1; $m1 = $cx * $b2 + $x * $b3; $b = (int) ($cy * $m0 + $y * $m1); return ($r << 16) | ($g << 8) | $b; } /** * @param $image * @param $x * @param $y * * @return int */ protected function getCol($image, $x, $y, $background) { $L = imagesx($image); $H = imagesy($image); if ($x < 0 || $x >= $L || $y < 0 || $y >= $H) { return $background; } return imagecolorat($image, $x, $y); } /** * @param $col * * @return array */ protected function getRGB($col) { return array( (int) ($col >> 16) & 0xff, (int) ($col >> 8) & 0xff, (int) ($col) & 0xff, ); } /** * Validate the background image path. Return the image type if valid * * @param string $backgroundImage * @return string * @throws Exception */ protected function validateBackgroundImage($backgroundImage) { // check if file exists if (!file_exists($backgroundImage)) { $backgroundImageExploded = explode('/', $backgroundImage); $imageFileName = count($backgroundImageExploded) > 1? $backgroundImageExploded[count($backgroundImageExploded)-1] : $backgroundImage; throw new Exception('Invalid background image: ' . $imageFileName); } // check image type $finfo = finfo_open(FILEINFO_MIME_TYPE); // return mime type ala mimetype extension $imageType = finfo_file($finfo, $backgroundImage); finfo_close($finfo); if (!in_array ($imageType, $this->allowedBackgroundImageTypes)) { throw new Exception('Invalid background image type! Allowed types are: ' . join(', ', $this->allowedBackgroundImageTypes)); } return $imageType; } /** * Create background image from type * * @param string $backgroundImage * @param string $imageType * @return resource * @throws Exception */ protected function createBackgroundImageFromType($backgroundImage, $imageType) { switch ($imageType) { case 'image/jpeg': $image = imagecreatefromjpeg($backgroundImage); break; case 'image/png': $image = imagecreatefrompng($backgroundImage); break; case 'image/gif': $image = imagecreatefromgif($backgroundImage); break; default: throw new Exception('Not supported file type for background image!'); break; } return $image; } }